Abstract
Bioprinting can fabricate structures based on layer-by-layer deposition of biomaterials. Bioprinting of animal cells shows great promise for tissue regeneration and tissue research. Plant cells can also be used when synthesizing bioink. Bioprinting with bioink that has been synthesized with plant cells instead of animal cells is called green bioprinting. Green bioprinting offers greater spatial control over the growth of plant matter by immobilizing cells. It is known that certain variables affect the growth and propagation (cellular reproduction) of cells in green bioprinted constructs post bioprinting. These variables include accessibility to components required for photosynthesis, such as nutrients, moisture and light. However, multiple parameters can also vary during the extrusion of bioink in the bioprinting process, including extrusion pressure, extrusion temperature, needle diameter, and printing speed. This paper reports a study to examine the effects of needle diameter during bioprinting on the growth of Chlamydomonas reinhardtii algae cells in green bioprinted constructs. Growth of Chlamydomonas reinhardtii algae cells was quantified by measuring cell count. The constructs were bioprinted with needle diameters of 22 gauge, 25 gauge, and 27 gauge. It was found that decreasing needle diameter was correlated with decreased cell count on the second and fifth days post bioprinting. Furthermore, the magnitude of cell count increase between the second and the fifth days post bioprinting decreased with decreasing needle diameter. Future research is needed to examine the effects of other printing parameters on cell growth.
